N-([1,2,4]triazoloazinyl)thiophenesulfonamide compounds and their use as herbicides

ABSTRACT

N-(Triazolo[1,5-a]pyrimidinyl)thiophenesulfonamide compounds were prepared from appropriately substituted 2-amino[1,2,4]triazolo[1,5-a]pyrimidine compounds and appropriately substituted thiophenesulfonyl chloride compounds. The compounds were found to be useful as herbicides.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. application Ser. No. 10/000,873filed Nov. 2, 2001, now U.S. Pat. No. 6,518,222, filed Feb. 11, 2003,claiming the benefits of U.S. Provisional Application No. 60/246,115filed Nov. 3, 2000.

BACKGROUND OF THE INVENTION

The present invention relates to substituted thiophenesulfonamidecompounds, to herbicidal compositions containing the compounds, and tothe utility of the compounds for the control of unwanted vegetation.

The control of unwanted vegetation by means of chemical agents, i.e.,herbicides, is an important aspect of modern agriculture and landmanagement. While many chemicals that are useful for the control ofunwanted vegetation are known, new compounds that are more effectivegenerally, are more effective for specific plant species, are lessdamaging to desirable vegetation, are safer to man or the environment,are less expensive to use, or have other advantageous attributes aredesirable.

Many substituted benzenesulfonamide compounds are known and certain ofthem are known to possess herbicidal activity. For example, certainN-([1,2,4]triazolo[1,5-a]pyrimidin-2-yl)benzenesulfonamide compounds andtheir herbicidal utility were disclosed in U.S. Pat. No. 4,638,075 andcertain N-([1,2,4]triazolo[1,3,5]triazin-2-yl)benzenesulfonamidecompounds were disclosed in U.S. Pat. No. 4,685,958. In addition,certain N-([1,2,4]triazolo[1,5-c]pyrimidin-2-yl)benzenesulfonamide,N-([1,2,4]triazolo[1,5-c]pyrimidin-2-yl)pyridinesulfonamide,N-([1,2,4]triazolo[1,5-a]pyridin-2-yl)benzenesulfonamide, andN-([1,2,4]triazolo[1,5-a]pyridin-2-yl)pyridinesulfonamide compounds weredisclosed in U.S. Pat. No. 5,858,924. Certain N-phenyl arylsulfonamidecompounds are also known and are known to possess herbicidal activity.For example, certain N-(substitutedphenyl)[1,2,4]triazolo[1,5-c]pyrimidin-2-sulfonamide compounds weredisclosed in U.S. Pat. No. 5,163,995 and certain N-(substitutedphenyl)[1,2,4]triazolo[1,5-a]pyridin-2-sulfonamide compounds weredisclosed in U.S. Pat. No. 5,571,775.

SUMMARY OF THE INVENTION

It has now been found that a class of novelN-(triazoloazinyl)thiophenesulfonamide compounds comprisingN-([1,2,4]triazolo[1,5-c]pyrimidin-2-yl)thiophenesulfonamide,N-([1,2,4]triazolo[1,5-a]pyrimidin-2-yl)thiophenesulfonamide, andN-([1,2,4]triazolo[1,5-a]pyridin-2-yl)thiophenesulfonamide compounds arepotent herbicides for the control of unwanted vegetation by eitherpreemergence or post-emergence application. The invention includesN-(triazoloazinyl)thiophenesulfonamide compounds of Formula I:

wherein

X represents CH or

Y represents CZ or N with the proviso that X and Y are not both N;

W represents H or OR with the proviso that when Y is CZ, then W is H;

Z represents R, OR or halo;

D and E represent S or CB with the proviso that one of D or E is S;

A and B independently represent H, halo, CF₃, R, OR′ or CO₂R″;

T represents H, SO₂R″, C(O)R″, C(O)OR″, C(O)NR″₂, or CH₂CH₂C(O)OR″;

R represents CH₃ or CH₂CH₃;

R′ represents C₁-C₄ alkyl, C₃-C₄ alkenyl, or C₃-C₄ alkynyl eachoptionally possessing up to two chloro, bromo or O(C₁-C₄)alkylsubstituents or up to the maximum possible number of fluorosubstituents;

R″ represents H or C₁-C₄ alkyl;

and, when T represents H, the agriculturally acceptable salts thereof.

Compounds wherein A represents OR′ or B represents CO₂R″ when Drepresents S and T represents H are among the preferred compounds of theinvention.

The invention further includes compositions containing herbicidalamounts of compounds of Formula I in combination with one or moreagriculturally acceptable adjuvants or carriers and the use of thecompounds of Formula I as herbicides. The use of suitable compounds ofthe invention to achieve total vegetation control is generallypreferred. Both grassy and broadleaf weeds can be controlled.Post-emergence application of the compounds to undesirable vegetation isgenerally preferred.

DETAILED DESCRIPTION OF THE INVENTION

The N-(triazoloazinyl)thiophenesulfonamide compounds of the inventioncan generally be described as substitutedN-([1,2,4]triazolo[1,5-c]pyrimidin-2-yl)thiophenesulfonamide,N-([1,2,4]triazolo[1,5-a]pyrimidin-2-yl)thiophenesulfonamide, andN-([1,2,4]triazolo[1,5-a]pyridin-2-yl)thiophenesulfonamide compounds.They can be characterized as substituted thiophenesulfonamide compoundspossessing, on the amide nitrogen atom, a substituted[1,2,4]triazolo[1,5-c]pyrimidin-2-yl, a substituted[1,2,4]triazolo[1,5-a]pyrimidin-2-yl or a substituted[1,2,4]triazolo[1,5-a]pyridin-2-yl moiety.

The herbicidal compounds of the invention areN-(triazoloazinyl)thiophenesulfonamide compounds of generic Formula I:

Such compounds in which X represents N contain a substitutedN-([1,2,4]triazolo[1,5-c]pyrimidin-2-yl) moiety, those in which Yrepresents N contain a substitutedN-([1,2,4]triazolo[1,5-a]pyrimidin-2-yl) moiety and those in which Xrepresents C—H and Y represents C—Z contain a substitutedN-([1,2,4]triazolo[1,5-a]pyridin-2-yl) moiety. Compounds in which Erepresents S are 2-thiophenesulfonamide compounds and compounds in whichD represents S are 3-thiophenesulfonamide compounds. The compounds arefurther characterized by possessing a methoxy or an ethoxy substituentadjacent to the bridgehead nitrogen in the 6-membered ring portion ofthe triazoloazine ring and by possessing at least one substituent (A)adjacent to the sulfonamide on the thiophene ring.

The compounds of the invention include compounds of Formula I wherein Xis N or CH.

Compounds in which X is N are often preferred. However, compounds inwhich X is CH are sometimes preferred.

The compounds of the invention include compounds of Formula I wherein Yis N, provided that X is not also N, or CZ in which Z is methyl, ethyl,methoxy, ethoxy or halo. Compounds in which Y is CZ are often preferred.However, compounds in which Y is N are sometimes preferred. Compounds inwhich Z is methoxy are often preferred.

Compounds of the invention include compounds of Formula I wherein D andE represent S or CB, provided that one and only one of D or E is S. Thethiophene-3-sulfonamides in which D represents S are usually preferred.

Compounds of the invention include compounds of Formula I wherein A andB independently represent H, halo, CF₃, R, OR′ or CO₂R″. A is preferablyOR′ or CO₂R″, and most preferably OR′.

Compounds of the invention include compounds of Formula I wherein Wrepresents H or OR provided that when Y is CZ, W is H. When Y is N, W ispreferably methoxy.

For compounds of the present invention, R can be CH₃ or CH₂CH₃. For OR,R is preferably CH₃.

For compounds of the present invention, R′ can be C₁-C₄ alkyl, C₃-C₄alkenyl, or C₃-C₄ alkynyl each optionally possessing up to two chloro,bromo or O(C₁-C₄)alkyl substituents or up to the maximum possible numberof fluoro substituents. For OR′, R′ is preferably C₁-C₄ alkyl optionallypossessing up to two chloro, bromo or O(C₁-C₄)alkyl substituents or upto the maximum possible number of fluoro substituents.

The compounds of Formula I include those wherein T represents hydrogen,an alkylsulfonyl group (SO₂R″), an acyl group (C(O)R″), analkoxycarbonyl group (C(O)OR″), an aminocarbonyl group (C(O)NR″₂), or a2-(alkoxycarbonyl) ethyl group (CH₂CH₂C(O)OR″). Such compounds wherein Trepresents hydrogen are preferred. The invention further includes theagriculturally acceptable salts of compounds of the Formula I wherein Trepresents hydrogen.

For compounds of the present invention, R″ can be H or C₁-C₄ alkyl. R″is preferably CH₃ or CH₂CH₃.

Compounds of Formula I which possess each possible combination ofpreferred, more preferred, most preferred, desirable, and specialinterest substituents are, further, considered to be importantembodiments of the invention.

The terms alkyl, alkenyl, and alkynyl (including when modified as inhaloalkyl and alkoxy) as used herein include straight chain, branchedchain, and cyclic groups. Thus, typical alkyl groups are methyl, ethyl,1-methylethyl, propyl, 1,1-dimethylethyl and cyclopropyl. Methyl andethyl are often preferred. Alkyl groups are sometimes referred to hereinas normal (n), iso (i), secondary (s) or tertiary (t). Typical alkylwith up to the maximum possible number of fluoro substituents includetrifluoromethyl, monofluoromethyl, 2,2,2-trifluoroethyl,2,3-difluoropropyl, and the like; trifluoromethyl is often preferred.The term halogen includes fluorine, chlorine, bromine, and iodine.

The term “agriculturally acceptable salts” is employed herein to denotecompounds wherein the acidic sulfonamide proton of the compound ofFormula I is replaced by a cation which itself is neither herbicidal tocrop plants being treated nor significantly deleterious to theapplicator, the environment, or the ultimate user of any crop beingtreated. Suitable cations include, for example, those derived fromalkali or alkaline earth metals and those derived from ammonia andamines. Preferred cations include sodium, potassium, magnesium, andaminium cations of the formula:

R²R³R⁴NH⁺

wherein R², R³, and R⁴ each, independently represents hydrogen or(C₁-C₁₂)alkyl, (C₃-C₁₂)cycloalkyl, or (C₃-C₁₂)alkenyl, each of which isoptionally substituted by one or more hydroxy, (C₁-C₈)alkoxy,(C₁-C₈)alkylthio or phenyl groups; provided that R², R³, and R⁴ aresterically compatible. Additionally, any two of R², R³ and R⁴ togethermay represent an aliphatic difunctional moiety containing 1 to 12 carbonatoms and up to two oxygen or sulfur atoms. Salts of the compounds ofFormula I can be prepared by treatment of compounds of Formula I whereinV represents hydrogen with a metal hydroxide, such as sodium hydroxide,potassium hydroxide or magnesium hydroxide, or an amine, such asammonia, trimethylamine, hydroxyethylamine, bisallylamine,2-butoxyethylamine, morpholine, cyclododecylamine or benzylamine.

The compounds of Table 1 and 2 are examples of the compounds of theinvention. Some of the specifically preferred compounds of Formula I,which vary depending on the weed species to be controlled, the croppresent (if any), and other factors, include the following compounds ofTable 1 and 2:N-(5,8-dimethoxy[1,2,4]triazolo[1,5-c]pyrimidin-2-yl)-4-methoxythiophene-3-sulfonamideandN-(5,8-dimethoxy[1,2,4]triazolo[1,5-c]pyrimidin-2-yl)-2-carboxymethylthiophene-3-sulfonamide.

TABLE 1 SULFONAMIDE COMPOUNDS

Melting Elem. Anal. Cpd. Point, Calc./Found No. A B X Y W Form ° C. % C% H % N 1 OCH₃ H N C—OCH₃ H Tan 227-228 38.81 3.53 18.86 Powder 38.323.49 18.91 2 OCH₃ H N C—Cl H Pink 226-227 35.16 2.68 18.64 Powder 35.502.83 18.30 3 OCH₃ Cl N C—OCH₃ H White 221-222 35.52 2.98 17.26 Powder35.65 2.94 16.99 4 OCH₃ Cl CH N OCH₃ White 218-219 35.52 2.98 17.26Powder 35.44 2.89 16.91 5 OCH₃ CF₃ CH N OCH₃ Tan 218-219 35.54 2.7515.94 Powder 35.77 2.76 15.51

TABLE 2 SULFONAMIDE COMPOUNDS

Melting Elem. Anal. Cpd. Point, Calc./Found No. A B X Y W Form ° C. % C% H % N  6 H CO₂CH₃ N C—OCH₃ H Tan 277-279 39.09 3.38 17.53 Powder 38.723.13 17.09  7 OCH₃ H N C—OCH₃ H White 236-237 38.81 3.53 18.86 Powder39.05 3.54 18.55  8 H OCH₃ N C—OCH₃ H Gray 220-221 38.81 3.53 18.86Powder 38.83 3.45 18.66  9 H OCH₃ N C—CH₃ H White 220-221 40.56 3.6919.71 Powder 40.59 3.60 19.65 10 OCH₃ CF₃ N C—OCH₃ H Tan 231-232 35.542.75 15.94 Powder 35.28 2.71 15.67 11 OC₂H₅ H CH C—OCH₃ H White 246-24743.74 4.20 14.57 Powder 43.52 4.19 14.32 12 OC₂H₅ H CH N OCH₃ Tan194-195 40.51 3.92 18.17 Powder 40.16 3.87 17.91 13 OC₂H₅ H N C—OCH₃ HWhite 223-224 40.51 3.92 18.17 Powder 40.18 3.89 17.89 14 OCH₃ H N C—ClH White 208-209 35.16 2.68 18.64 Powder 34.95 2.68 18.61 15 OCH₃ H CH NOCH₃ White 218-219 38.81 3.53 18.86 Powder 38.63 3.35 18.60 16 OCH₃ H CHC—OCH₃ H White 245-246 42.16 3.81 15.13 Powder 42.42 3.80 15.06 17 OCH₃H N C—CH₃ H White 230-231 40.56 3.69 19.71 Powder 40.36 3.61 19.68 18OCH₃ Cl N C—OCH₃ H Tan 222-223 35.52 2.98 17.26 Powder 35.53 2.99 17.1019 OCH₃ Cl CH N OCH₃ White 205-206 35.52 2.98 17.26 Powder 35.16 2.9017.23 20 OCH₃ Cl N C—Cl H White 208-210 32.21 2.21 17.07 Powder 32.142.21 16.97 21 OCH₃ Cl N C—CH₃ H White 212-214 36.97 3.10 17.97 Powder36.78 3.04 17.70 22 OCH₃ CH₃ N C—Cl H White 220-221 36.97 3.10 17.97Powder 37.14 3.14 17.82 23 OCH₃ CH₃ N C—OCH₃ H White 219-220 40.51 3.9218.17 Powder 40.67 3.98 17.90 24 OCH₃ CH₃ CH N OCH₃ White 209-210 40.513.92 18.17 Powder 39.98 3.83 18.27 25 OCH₃ CF₃ CH N OCH₃ Tan 219-22135.54 2.75 15.94 Powder 35.66 2.78 15.31

The compounds of Formula I wherein T represents hydrogen can be preparedby the reaction of a substituted 2-amino[1,2,4]triazoloazine compound ofFormula II:

with a thiophenesulfonyl chloride compound of Formula III:

wherein A, D, E, R, W, X and Y are as defined for compounds of FormulaI. The reaction can be carried out by combining approximately equalmolar amounts of the two compounds in a polar, aprotic solvent, such asacetonitrile, and adding pyridine and a catalytic amount (5 to 25 molarpercent of the sulfonyl chloride compound) of dimethyl sulfoxide at roomtemperature. Additional sulfonyl chloride compound, pyridine, anddimethyl sulfoxide are added, if necessary, to complete the reaction.The reactions take from a few hours to several days to go to completion.Means to exclude moisture, such as a dry nitrogen blanket, are employed.The compounds of Formula I obtained, which are solids with lowsolubility in many common organic solvents and in water, can berecovered using conventional means.

N-(triazoloazinyl)thiophenesulfonamide compounds of Formula I wherein Trepresents other than hydrogen can be prepared from the correspondingcompounds of Formula I wherein T represents hydrogen by acylation underreaction conditions known in the art for related sulfonamide acylationreactions. Suitable acylating agents include alkanoyl chloridecompounds, such as propionyl chloride or trifluoroacetyl chloride;chloroformate ester compounds, such as 2-methoxyethyl chloroformate;carbamoyl chloride compounds, such as N′,N′-diallylcarbamoyl chloride,and alkyl isocyanate compounds, such as 2-chloroethyl isocyanate.

Compounds of Formula I having alkoxy substituents in the triazoloazinering can be prepared from the corresponding halo compounds of Formula Iby treatment with an appropriate alkoxide using the general methods forsuch replacements known in the art. Halo substituents in some positionsare generally more easily replaced than are halo substituents in otherpositions depending on the triazoloazine ring system and can beselectively replaced.

Many 2-amino[1,2,4]triazolo[1,5-a]pyridine compounds of Formula II (Xrepresents C—H and Y represents C—Z) can be prepared by the reaction ofappropriately substituted N-(2-pyridinyl)-N′-carboethoxythioureacompounds of the formula:

wherein Z is as defined for compounds of Formula I and L is OR or halo,with hydroxylamine. The reaction is typically carried out in a solventsuch as ethanol and requires heating for a few hours. The hydroxylamineis typically generated by neutralization of the hydrochloride with ahindered tertiary amine, such as diisopropylethylamine, or an alkalimetal alkoxide, such as sodium ethoxide. The desired compounds ofFormula II can be recovered by conventional means, such as by removal ofthe volatile components of the reaction mixture by evaporation, and canbe purified by conventional means, such as by extraction with waterand/or other solvents in which they are sparingly soluble. TheN-(2-pyridinyl)-N′-carboethoxythiourea compound starting materials forthis method can be obtained by treatment of appropriately substituted2-aminopyridine compounds with ethoxycarbonyl isothiocyanate. Thereaction is generally carried out in an inert organic solvent at ambienttemperatures. The overall method is further described in U.S. Pat. No.5,571,775.

The substituted 2-aminopyridine compound starting materials for themethod described above are known in the art or can be prepared by themethods disclosed herein or by general methods known in the art.

Compounds of Formula II wherein X represents C—H can also be preparedfrom appropriately substituted 2-cyanoaminopyridine compounds by themethod disclosed by B. Vercek et al. in Monatshefte fur Chemie, 114,789-798 (1983). Additional methods of preparation of such compounds weredisclosed by K. T. Potts et al. in Journal of Organic Chemistry, 31,265-273 (1966).

Compounds of Formula II wherein X represents N, i.e.,2-amino[1,2,4]triazolo[1,5-c]pyrimidine compounds, can be prepared from4-hydrazinopyrimidine compounds of the formula:

wherein Q represents methylthio or chloro and Z is as defined forcompounds of Formula I. The hydrazinopyrimidine compound is firsttreated with cyanogen bromide to produce the hydrobromide of a3-amino-8-substituted-5-substituted[1,2,4]triazolo[4,3-c]pyrimidinecompound of the formula:

wherein Q represents methylthio or chloro and Z is as defined forcompounds of Formula I. The reaction is generally carried out in anorganic solvent, such as isopropyl alcohol, at ambient temperature. Theproducts can be recovered by conventional means, such as by adding anon-polar solvent, for example diethyl ether, and collecting the solidthat forms by filtration. The above intermediates wherein Q representsmethylthio can then be converted into the desired compounds of FormulaII wherein Q represents an alkoxy group by treatment with an alkalimetal alcoholate, such as sodium methylate or potassium ethylate, andethyl acrylate in the corresponding alcohol as a solvent. The compoundrearranges and the methylthio moiety is replaced by the alkoxy moietyderived from the alcohol of the medium. The reaction is generallycarried out at temperatures below 25° C. The desired compounds ofFormula II can be recovered by neutralizing with acetic acid andcollecting the solids that form by filtration or other conventionalmeans. Compounds of Formula II wherein X represents N and Q representschloro can be obtained from the corresponding [4,3-c] intermediatewherein Q represents chloro by isomerization with a trialkylamine base.The 4-hydrazinopyrimidine compound starting materials for these methodscan be prepared from the corresponding 4-chloropyrimidine compounds,which are well-known in the art, by reaction with hydrazine.

Other methods of preparation of compounds of Formula II wherein Xrepresents N are disclosed by G. W. Miller, et al., J. Chemical Society,1965, page 3357 and 1963, page 5642.

Compounds of Formula II wherein Y represents N, e.g.,2-amino[1,2,4]triazolo[1,5-a]pyrimidine compounds, can be prepared bythe reaction of N-(4,6-dialkoxypyrimidin-2-yl)-N′-carboethoxythiourea ofthe formula:

wherein R is as defined for Formula I with hydroxylamine. The reactionis typically carried out in a solvent such as ethanol and requiresheating for a few hours. The hydroxylamine is typically generated byneutralization of the hydrochloride with a hindered tertiary amine, suchas diisopropylethylamine, or an alkali metal alkoxide, such as sodiumethoxide. The desired compound of Formula II can be recovered byconventional means, such as by removal of the volatile components of thereaction mixture by evaporation, and can be purified by conventionalmeans, such as by extraction with water and/or other solvents in whichthey are sparingly soluble. TheN-(4,6-dialkoxypyrimidin-2-yl)-N′-carboethoxythiourea starting materialfor this method can be obtained by treatment of2-amino-4,6-dialkoxypyrimidine with ethoxycarbonyl isothiocyanate. Thereaction is generally carried out in an inert organic solvent at ambienttemperatures. The overall method is further described in U.S. Pat. No.5,571,775.

The 2-amino-4,6-dialkoxypyrimidine starting material for the methoddescribed above is known in the art.

The substituted thiophenesulfonyl chloride starting materials of FormulaIII can be prepared by the methods disclosed herein or by general orspecific methods known in the art. Many such compounds can be preparedby lithiation of the corresponding thiophene compound with butyllithium, reaction of the thienyl lithium compound obtained with SO₂, andthen chlorination with N-chlorosuccinimide. In each of these reactionsteps, conditions generally known for such processes were used. Thienyllithium compounds can also be prepared by halogen-metal exchangereactions of halothiophenes with n-butyl lithium. Many propyl orbenzylthiothiophenes can also be prepared by alkylation of thecorresponding mercaptothiophene compound using standard methods or byreaction of the thienyl lithium compounds with the appropriatedisulfide. Subsequent chloroxidation with, for example, chlorine in thepresence of water provides the desired sulfonyl chlorides.

Compounds of Formula III include substituted thiophene-2-sulfonylchloride compounds of the formula:

and substituted thiophene-3-sulfonyl chloride compounds of the formula:

wherein A and B independently represent H, halo, CF₃, R, OR′ or CO₂R″.The substituted thiophene-3-sulfonyl chlorides are preferred,particularly those in which A or B are OR′ or CO₂R″.

While it is possible to utilize theN-(triazoloazinyl)thiophenesulfonamide compounds of Formula I directlyas herbicides, it is preferable to use them in mixtures containing anherbicidally effective amount of the compound along with at least oneagriculturally acceptable adjuvant or carrier. Suitable adjuvants orcarriers should not be phytotoxic to valuable crops, particularly at theconcentrations employed in applying the compositions for selective weedcontrol in the presence of crops, and should not react chemically withthe compounds of Formula I or other composition ingredients. Suchmixtures can be designed for application directly to weeds or theirlocus or can be concentrates or formulations that are normally dilutedwith additional carriers and adjuvants before application. They can besolids, such as, for example, dusts, granules, water dispersiblegranules, or wettable powders, or liquids, such as, for example,emulsifiable concentrates, solutions, emulsions or suspensions.

Suitable agricultural adjuvants and carriers that are useful inpreparing the herbicidal mixtures of the invention are well known tothose skilled in the art.

Liquid carriers that can be employed include water, toluene, xylene,petroleum naphtha, crop oil, acetone, methyl ethyl ketone,cyclohexanone, trichloroethylene, perchloroethylene, ethyl acetate, amylacetate, butyl acetate, propylene glycol monomethyl ether and diethyleneglycol monomethyl ether, methanol, ethanol, isopropanol, amyl alcohol,ethylene glycol, propylene glycol, glycerine, N-methyl-2-pyrrolidinone,and the like. Water is generally the carrier of choice for the dilutionof concentrates.

Suitable solid carriers include talc, pyrophyllite clay, silica,attapulgus clay, kieselguhr, chalk, diatomaceous earth, lime, calciumcarbonate, bentonite clay, Fuller's earth, cotton seed hulls, wheatflour, soybean flour, pumice, wood flour, walnut shell flour, lignin,and the like.

It is frequently desirable to incorporate one or more surface-activeagents into the compositions of the present invention. Suchsurface-active agents are advantageously employed in both solid andliquid compositions, especially those designed to be diluted withcarrier before application. The surface-active agents can be anionic,cationic or nonionic in character and can be employed as emulsifyingagents, wetting agents, suspending agents, or for other purposes.Typical surface active agents include salts of alkyl sulfates, such asdiethanolammonium lauryl sulfate; alkylarylsulfonate salts, such ascalcium dodecylbenzenesulfonate; alkylphenol-alkylene oxide additionproducts, such as nonylphenol-C₁₈ ethoxylate; alcohol-alkylene oxideaddition products, such as tridecyl alcohol-C₁₆ ethoxylate; soaps, suchas sodium stearate; alkylnaphthalenesulfonate salts, such as sodiumdibutylnaphthalenesulfonate; dialkyl esters of sulfosuccinate salts,such as sodium di(2-ethylhexyl) sulfosuccinate; sorbitol esters, such assorbitol oleate; quaternary amines, such as lauryl trimethylammoniumchloride; polyethylene glycol esters of fatty acids, such aspolyethylene glycol stearate; block copolymers of ethylene oxide andpropylene oxide; and salts of mono and dialkyl phosphate esters.

Other adjuvants commonly utilized in agricultural compositions includecompatibilizing agents, antifoam agents, sequestering agents,neutralizing agents and buffers, corrosion inhibitors, dyes, odorants,spreading agents, penetration aids, sticking agents, dispersing agents,thickening agents, freezing point depressants, antimicrobial agents, andthe like. The compositions can also contain other compatible components,for example, other herbicides, herbicide safeners, plant growthregulants, fungicides, insecticides, and the like and can be formulatedwith liquid fertilizers or solid, particulate fertilizer carriers suchas ammonium nitrate, urea and the like.

The concentration of the active ingredients in the herbicidalcompositions of this invention is generally from about 0.001 to about 98percent by weight. Concentrations from about 0.01 to about 90 percent byweight are often employed. In compositions designed to be employed asconcentrates, the active ingredient is generally present in aconcentration from about 5 to about 98 weight percent, preferably about10 to about 90 weight percent. Such compositions are typically dilutedwith an inert carrier, such as water, before application. The dilutedcompositions usually applied to weeds or the locus of weeds generallycontain about 0.001 to about 5 weight percent active ingredient andpreferably contain about 0.01 to about 0.5 percent.

The present compositions can be applied to weeds or their locus by theuse of conventional ground or aerial dusters, sprayers, and granuleapplicators, by addition to irrigation water, and by other conventionalmeans known to those skilled in the art.

The compounds of Formula I have been found to be useful preemergence(including pre-plant) and postemergence herbicides. Postemergenceapplications are generally preferred. The compounds are effective in thecontrol of both broadleaf and grassy weeds. While each of theN-(triazoloazinyl)thiophenesulfonamide compounds encompassed by FormulaI is within the scope of the invention, the degree of herbicidalactivity, crop selectivity, and spectrum of weed control obtained variesdepending upon the substituents and other features present. Thecompounds can be employed at higher, non-selective rates of applicationto control essentially all of the vegetation in an area. In some cases,the compounds can also be employed at lower, selective rates ofapplication for the control of undesirable vegetation in grass crops orin broadleaf crops. In some instances, the selectivity can often beimproved by the use of safeners.

The term herbicide is used herein to mean an active ingredient thatcontrols or adversely modifies the growth of plants. An herbicidallyeffective or vegetation controlling amount is an amount of activeingredient which causes an adversely modifying effect and includesdeviations from natural development, killing, regulation, desiccation,retardation, and the like. The terms plants and vegetation are meant toinclude germinant seeds, emerging seedlings and established vegetation.

Herbicidal activity is exhibited by the compounds of the presentinvention when they are applied directly to the plant or to the locus ofthe plant at any stage of growth or before planting or emergence. Theeffect observed depends upon the plant species to be controlled, thestage of growth of the plant, the application parameters of dilution andspray drop size, the particle size of solid components, theenvironmental conditions at the time of use, the specific compoundemployed, the specific adjuvants and carriers employed, the soil type,and the like, as well as the amount of chemical applied. These and otherfactors can be adjusted as is known in the art to promote non-selectiveor selective herbicidal action. Generally, it is preferred to apply thecompounds of Formula I postemergence to relatively immature plants toachieve the maximum control of weeds.

Application rates of about 0.001 to about 1 Kg/Ha are generally employedin postemergence operations; for preemergence applications, rates ofabout 0.01 to about 2 kg/ha are generally employed. The higher ratesdesignated generally give non-selective control of a broad variety ofundesirable vegetation. The lower rates typically give selective controland, by judicious election of compounds, timing, and rates ofapplication, can be employed in the locus of crops.

The compounds of the present invention (Formula I) are often applied inconjunction with one or more other herbicides to obtain control of awider variety of undesirable vegetation. When used in conjunction withother herbicides, the presently claimed compounds can be formulated withthe other herbicide or herbicides, tank mixed with the other herbicideor herbicides, or applied sequentially with the other herbicide orherbicides. Some of the herbicides that can be employed beneficially incombination with the compounds of the present invention includesubstituted triazolopyrimidinesulfonamide compounds, such as diclosulam,cloransulam-methyl and flumetsulam. Other herbicides such asacifluorfen, bentazon, chlorimuron, clomazone, lactofen,carfentrazone-methyl, fumiclorac, fluometuron, fomesafen, imazaquin,imazethapyr, linuron, metribuzin, fluazifop, haloxyfop, glyphosate,glufosinate, 2,4-D, acetochlor, metolachlor, sethoxydim, nicosulfuron,clopyralid, fluroxypyr, metsulfuron-methyl, amidosulfuron, tribenuron,and others can also be employed. It is generally preferred to use thecompounds in conjunction with other herbicides that have a similar cropselectivity. It is further usually preferred to apply the herbicides atthe same time, either as a combination formulation or as a tank mix.

The compounds of the present invention can generally be employed incombination with a wide variety of known herbicide safeners, such ascloquintocet, mefenpyr, furilazole, dichlormid, benoxacor, flurazole,fluxofenim, daimuron, dimepiperate, thiobencarb, and fenclorim, toenhance their selectivity. Herbicide safeners that act by modifying themetabolism of herbicides in plants by enhancing the activity ofcytochrome P-450 oxidases are usually especially effective. This isoften a preferred embodiment of the invention. The compounds canadditionally be employed to control undesirable vegetation in many cropsthat have been made tolerant to or resistant to herbicides by geneticmanipulation or by mutation and selection. For example, crops that havebeen made tolerant or resistant to herbicides in general or toherbicides that inhibit the enzyme acetolactate synthase in sensitiveplants can be treated.

EXAMPLES

The following Examples are presented to illustrate the various aspectsof this invention and should not be construed as limitations to theclaims.

1. Preparation of Methyl 4-Bromo-3-hydroxy-2-thiophenecarboxylate

To a solution of 31 g (0.2 mole) of methyl3-hydroxy-2-thiophenecarboxylate in 400 milliliters (mL) of glacialacetic acid was added 31.3 g (0.2 mole) of Br₂ over 45 minutes (min).After 16 hours (hr), another 31.3 g of Br₂ was added over 6 hr and thereaction was stirred another 18 hr. The reaction mixture was poured intoaqueous NaHSO₃ and extracted with ether. The organic phase wasseparated, washed with water (2×300 mL), dried over MgSO₄, filtered andconcentrated to a viscous oil. This oil (47 g) was dissolved in 200 mLof methanol and after 48 hr at 15° C., 36 g (77%) of light pink crystalswere collected by filtration. mp 79-80° C. ¹H NMR (300 MHz, CDCl₃): δ9.8 (br, 1H); 7.4 (s, 1H); 3.9 (s, 3H). Anal. Calc'd for C₆H₅BrO₃S: C,30.04; H, 2.23; S, 13.52. Found: C, 30.04; H, 1.92; S, 14.01.

2. Preparation of Methyl 4-Bromo-3-methoxy-2-thiophenecarboxylate

To a solution of 36 g (0.15 mole) of methyl4-bromo-3-hydroxy-2-thiophenecarboxylate in 300 mL of dimethyl sulfoxide(DMSO) was added 32 g (0.23 mole) of methyl iodide and then 32 g ofpowdered K₂CO₃. After 2 hr, the reaction mixture was poured into waterand extracted with ether. The organic phase was washed with water (4×200mL), dried over MgSO₄, filtered and concentrated to give 36 g of acolorless solid. ¹H NMR (300 MHz, CDCl₃): δ 7.4 (s, 1H); 4.0 (s, 3H);3.9 (s, 3H). Anal. Calc'd for C₇H₇BrO₃S: C, 33.48; H, 2.81; S, 12.77.Found: C, 33.18; H, 2.70; S, 12.49.

3. Preparation of 4-Bromo-2-carboxy-3-methoxy-thiophene

A solution of 37.5 g (0.15 mole) of methyl4-bromo-3-methoxy-2-thiophenecarboxylate and 12 g of KOH (0.18 mole) ina mixture of 250 mL of methanol and 100 mL of water was refluxed for 2hr. The reaction mixture was cooled and most of the methanol was removedin vacuo. The solution was partitioned with ether and dilute aqueousHCl. The organic phase was separated dried over MgSO₄, filtered andconcentrated and dried under a vacuum to give 34 g (94%) of a colorlesssolid. mp 191-192° C. ¹H NMR (300 MHz, CDCl₃): δ 7.5 (s, 1H); 4.1 (s,3H). Anal. Calc'd for C₆H₅BrO₃S: C, 30.04; H, 2.23; S, 13.52. Found: C,29.89; H, 2.06; S, 13.14.

4. Preparation of 4-Bromo-2-carboxy-5-chloro-3-methoxythiophene

A solution of lithium diisopropylamine (LDA) was prepared at −10° C. bythe addition of 88.6 mL (0.22 mole) of 2.5 M n-butyllithium to asolution of 22.4 g (0.22 mole) of diisopropylamine in 150 mL of drytetrahydrofuran (THF). This was then slowly added to a colorlesssolution of 15 g (63 mmole) of 4-bromo-2-carboxy-3-methoxythiophene in200 mL of dry THF at −78° C. to give a deep red solution. After 1 hr, 60g (0.25 mole) of C₂Cl₆ was added and the reaction mixture allowed towarm slowly to room temperature. The reaction mixture was partitionedwith ether and dilute aqueous HCl. The organic phase was then extractedseveral times with 5% aqueous NaOH. The aqueous extracts were combined,acidified with 20% aqueous HCl and extracted with fresh ether. Theorganic layer was dried over MgSO₄, filtered and concentrated to give16.1 g (94%) of a tan solid. mp 191-192° C. ¹H NMR (300 MHz, CDCl₃): δ4.1 (s, 3H). Anal. Calc'd for C₆H₄BrClO₃S: C, 26.54; H, 1.48; S, 11.81.Found: C, 27.02; H, 1.55; S, 11.42.

5. Preparation of 4-Bromo-2-carboxy-3-methoxy-5-methylthiophene

A solution of LDA was prepared at −10° C. by the addition of 101 mL(0.26 mole) of 2.5 M n-butyllithium to a solution of 25.6 g (0.26 mole)of diisopropylamine in 150 mL of dry THF. This was then slowly added toa colorless solution of 15 g (63 mmole) of4-bromo-2-carboxy-3-methoxythiophene in 200 mL of dry THF at −78° C. togive a deep red solution. After 1 hr, this solution was cannulated intoa solution of 60 g (0.42 mole) of methyl iodide in 300 mL of dry THF at−35° C. The reaction mixture was partitioned with ether and diluteaqueous HCl. The organic layer was dried over MgSO₄, filtered andconcentrated to a light brown solid. This solid was recrystallized froma mixture of hexane and CH₂Cl₂ to give 11 g of a tan solid. mp 166-167°C. ¹H NMR (300 MHz, CDCl₃): δ 3.9 (s, 3H); 2.3 (s, 3H). Anal. Calc'd forC₇H₇BrO₃S: C, 33.48; H, 2.81; S, 12.77. Found: C, 33.47; H, 2.77; S,12.59.

6. Preparation of Methyl3-Methoxy-5-trifluoromethyl-2-thiophenecarboxylate

To a solution of 20 g (88 mmole) of methyl3-hydroxy-5-trifluoromethyl-2-thiophenecarboxylate in 200 mL of DMSO wasadded 37 g (260 mmole) of methyl iodide and 25 g (181 mmole) of powderedK₂CO₃. After 2 hr of stirring, the reaction mixture was poured intowater and extracted with ether. The organic phase was separated, washedwith water several times, dried over MgSO₄, filtered and concentrated togive 20 g of a nearly colorless solid. This solid was further purifiedby recrystallization from 12:1 hexane:ethyl acetate to give 10.5 g ofcolorless crystals. The mother liquor was concentrated and purified bycolumn chromatography to give another 8 g (87% yield). mp 78-79° C. ¹HNMR (300 MHz, CDCl₃): δ 7.2 (s, 1H); 4.0 (s, 3H); 3.9 (s, 3H). Anal.Calc'd for C₈H₇F₃O₃S: C, 40.00; H, 2.94; S, 13.35. Found: C, 39.87; H,2.94; S, 13.47.

7. Preparation of 3-Methoxy-5-trifluoromethyl-2-thiophenecarboxylic Acid

A solution of 2 g (14 mmole) ofmethyl-3-methoxy-5-trifluoromethyl-2-thiophenecarboxylate, 2 g (28mmole) of KOH in a mixture of 15 mL water and 50 mL of methanol wasrefluxed for 2 hr. The reaction mixture was partitioned with ether anddilute aqueous HCl. The organic phase was separated, dried over MgSO₄,filtered and concentrated to give 2.8 g (87%) of a colorless solid. mp131-132° C. ¹H NMR (300 MHz, CDCl₃): δ 7.2 (s, 1H); 4.1 (s, 3H). Anal.Calc'd for C₇H₅F₃O₃S: C, 37.17; H, 2.23; S, 14.18. Found: C, 36.96; H,2.19; S, 14.08.

8. Preparation of4-Benzylthio-3-methoxy-5-trifluoromethyl-2-thiophenecarboxylic Acid

To a solution of 3 g (13 mmole) of3-methoxy-5-trifluoromethyl-2-thiophenecarboxylic acid in 100 mL of dryTHF at −20° C. was added 5.3 ml (13 mmole) of 2.5 M n-butyllithium toform a slurry. To this slurry was added a solution of LDA, freshlyprepared by the addition of 2.0 g (19.7 mmole) of diisopropylamine and7.9 mL of 2.5 M n-butyllithium in 50 mL of dry THF. Over 2 hr at 0-5°C., the slurry gradually formed a dark solution, before a solution of9.8 g (40 mmole) of dibenzyldisulfide was added as a solution in THF.The reaction was stirred and allowed to warm to 15° C. before it waspartitioned with ether and dilute aqueous Na₂CO₃. The aqueous phase wasseparated, acidified with 10% aqueous HCl and extracted with freshether. The organic phase was separated, concentrated and then purifiedby reverse phase HPLC using a 50:50 mixture of acetonitrile and waterwith 0.5% H₃PO₄. After most of the acetonitrile was removed in vacuo,the product was recovered from the appropriate fraction by extractionwith ether. The organic phase was separated, dried over MgSO₄, filteredand concentrated to give 2 g (43%) of a tan solid. mp 146-147° C. ¹H NMR(300 MHz, CDCl₃): δ 9.6 (br, 1H); 7.2 (m, 5H); 4.12 (s, 3H); 4.09 (s,2H). Anal. Calc'd for C₁₄H₁₁F₃O₃S₂: C, 48.27; H, 3.18; S, 18.41. Found:C, 48.00; H, 3.14; S, 18.44.

9. Preparation of 3-Benzylthio-4-methoxy-2-trifluoromethylthiophene

A mixture of 3.6 g of4-benzylthio-3-methoxy-5-trifluoromethyl-2-thiophenecarboxylic acid and0.85 g of copper powder in 50 mL of quinoline was heated to 150° C. for15 min. The mixture was cooled and partitioned with ether and aqueousHCl. The organic phase was separated, dried over MgSO₄, filtered,concentrated and purified by column chromatography to give 2.2 g (71%)of an amber oil. ¹H NMR (300 MHz, CDCl₃): δ 7.2 (m, 5H); 6.4 (s, 1H);4.1 (s, 2H); 3.8 (s, 3H). Anal. Calc'd for C₁₃H₁₁F₃OS₂: C, 51.30; H,3.64; S, 21.07. Found: C, 51.13; H, 3.54; S, 21.02.

10. Preparation of 3-Bromo-4-methoxythiophene

A sample of 15 g of 4-bromo-3-methoxythiophene-2-carboxylic acid washeated to 200-220° C. at 140 mm vacuum for 40 min. A nearly colorlessoil (11 g) was collected by distillation. bp. 160-165° C. @ 80-85 mm.This oil was further purified by chromatography to give 8.8 g of acolorless oil. ¹H NMR (300 MHz, CDCl₃): δ 7.2 (d, 1H, J=3.5); 6.2 (d,1H, J=3.5); 3.9 (s, 3H). Anal. Calc'd for C₅H₅BrOS: C, 31.11; H. 2.61;S, 16.61. Found: C, 30.98; H, 2.61; S, 16.89.

The following decarboxylated thiophene compounds were preparedsimilarly:

3-Bromo-4-ethoxythiophene

bp 140-145° C. @ 35 mm. ¹H NMR (300 MHz, CDCl₃): δ 7.2 (d, 1H, J=3.5);6.2 (d, 1H, J=3.5); 4.1 (q, 2H, J=7); 1.5 (t, 3H, J=7). Anal. Calc'd forC₆H₇BrOS: C, 34.80; H, 3.41; S, 15.48. Found: C, 34.56; H, 3.36; S,15.44.

3-Bromo-2-chloro-4-methoxythiophene

bp 160-165° C. @ 10 mm. mp 63-64° C. ¹H NMR (300 MHz, CDCl₃): δ 6.1 (s,1H); 3.8 (s, 3H). Anal. Calc'd for C₅H₄BrClOS: C, 26.40; H, 1.77; S,14.09. Found: C, 26.63; H, 1.76; S, 13.95.

3-Bromo-4-methoxy-2-methylthiophene

bp 150-155° C. @ 10 mm. ¹H NMR (300 MHz, CDCl₃): δ 5.9 (s, 1H); 3.7 (s,3H); 2.3 (s, 3H). Anal. Calc'd for C₆H₇BrOS: C, 34.80; H, 3.41; S,15.48. Found: C, 34.66; H, 3.57; S, 15.60.

2-Chloro-4-methoxythiophene

bp 120-125° C. @ 15 mm. ¹H NMR (300 MHz, CDCl₃): δ 6.65 (d, 1H, J=2);6.0 (d, 1H, J=2); 3.8 (s, 3H). Anal. Calc'd for C₅H₅ClOS: C, 40.41; H,3.20; S, 21.57. Found: C, 40.21; H, 3.20; S, 21.43.

11. Preparation of 5-Chloro-2-chlorosulfonyl-3-methoxythiophene

To a solution of 3.8 g (26 mmol) of 2-chloro-4-methoxythiophene in 100mL of ether at −30° C. under nitrogen was slowly added 11.2 mL of 2.5 Mn-butyllithium. This solution was warmed briefly to room temperaturethen cooled to −60° C. This solution was then transferred into asolution of 4 g (85 mmol) of SO₂ in 300 mL of ether at −30° C. to give athick slurry. This slurry was diluted to facilitate stirring and allowedto warm to room temperature. The solids were collected by filtration andtaken directly into 75 mL of water before adding 75 mL of iso-propylalcohol. To this was added in portions, 3.8 g (29 mmol) ofN-chlorosuccinimide. After 30 min the solution was partitioned withether and dilute aq. NaHSO₃. The organic phase was separated, dried overMgSO₄, concentrated and purified by HPLC to give 3.1 g of an amber oil.¹H NMR (300 MHz, CDCl₃): δ 6.8 (s, 1H); 4.1 (s, 3H). Anal. Calc'd forC₅H₄Cl₂O₃S₂: C, 24.30; H, 1.63; S, 25.95. Found: C, 24.10; H, 1.59; S,25.65.

The following 2-chlorosulfonylthiophene compound was prepared similarly:

2-Chlorosulfonyl-3-methoxythiophene

mp 71-72° C. ¹H NMR (300 MHz, CDCl₃): δ 7.7 (d, 1H, J=5.6); 7.0 (d, 1H,J=5.6); 4.1 (s, 3H). Anal. Calc'd for C₅H₅ClO₃S₂: C, 28.24; H, 2.37; S,30.15. Found: C, 28.41; H, 2.33; S, 30.18.

12. Preparation of 3-chlorosulfonyl-2-methoxythiophene

To a solution of 9 g (47 mmol) of 3-bromo-2-methoxythiophene in 150 mLof dry THF at −78° C. was slowly added 19 mL of 2.5 M n-butyllithium.After 30 min, the solution was sparged with excess anhydrous SO₂ toprecipitate a colorless solid. This mixture was warmed to roomtemperature, diluted with ether and the solid collected by filtration.This solid was dissolved in 150 mL of an equal mixture of iso-propylalcohol and water. To this solution was added in portions, 6.7 g (50mmol) of N-chlorosuccinimide. After 15 min, the reaction solution waspartitioned with ether and dilute aqueous NaHSO₃. The organic phase wasseparated, dried over MgSO₄, filtered, concentrated and purified bycolumn chromatography to give 5.1 g of an amber oil. ¹H NMR (300 MHz,CDCl₃): δ 6.2 (S, 1H); 3.9 (s, 3H). Anal. Calc'd for C₅H₅ClO₃S₂: C,28.24; H, 2.37; S, 30.15. Found: C, 28.56; H, 2.57; S, 29.96.

The following 3-chlorosulfonylthiophene compounds were preparedsimilarly:

3-Chlorosulfonyl-4-methoxythiophene

¹H NMR (300 MHz, CDCl₃): δ 8.1 (d, 1H, J=3.8); 6.4 (d, 1H, J=3.8); 4.0(s, 3H). Anal. Calc'd for C₅H₅ClO₃S₂: C, 28.24; H, 2.37; S, 30.15.Found: C, 28.24; H, 2.37; S, 29.85.

3-Chlorosulfonyl-4-ethoxythiophene

¹H NMR (300 MHz, CDCl₃): δ 8.1 (d, 1H, J=3.5); 6.4 (d, 1H, J=3.5); 4.2(q, 2H, J=6.9); 1.2 (t, 3H, J=6.9). Anal. Calc'd for C₆H₇ClO₃S₂: C,31.79; H, 3.11; S, 28.28. Found: C, 32.07; H, 3.19; S, 27.97.

2-Chloro-3-chlorosulfonyl-4-methoxythiophene

¹H NMR (300 MHz, CDCl₃): δ 6.2 (s, 1H); 3.9 (s, 3H). Anal. Calc'd forC₅H₅Cl₂O₃S₂: C, 28.24; H, 2.37; S, 30.15. Found: C, 28.56; H, 2.57; S,29.96.

3-Chlorosulfonyl-4-methoxy-2-methylthiophene

¹H NMR (300 MHz, CDCl₃): δ 6.0 (s, 1H); 3.8 (s, 3H); 2.6 (s, 3H). Anal.Calc'd for C₆H₇ClO₃S₂: C, 28.24; H, 2.37; S, 30.15. Found: C, 28.56; H,2.57; S, 29.96.

13. Preparation of 3-Chlorosulfonyl-4-methoxy-2-trifluoromethylthiophene

A stirred mixture of 5.3 g (17.4 mmole) of3-benzylthio-4-methoxy-2-trifluoromethylthiophene in 250 mL of CH₂Cl₂and 250 mL of dilute aqueous HCl at 0° C. was sparged slowly with 4.7 gof Cl₂. The mixture was warmed to room temperature and the organic phasewas separated, dried over MgSO₄, filtered and concentrated to an amberoil. This oil was purified by HPLC to give 3 g of a colorless oil. ¹HNMR (300 MHz, CDCl₃): δ 6.6 (s, 1H); 4.0 (s, 3H). Anal. Calc'd forC₆H₄ClF₃O₃S₂: C, 25.68; H, 1.44; S, 22.85. Found: C, 25.98; H, 1.5; S,22.65.

14. Preparation of3-Amino-8-chloro-5-methylthio[1,2,4]triazolo[4,3-c]pyrimidineHydrobromide

A solution of 40 mL (120 mmol) of 3 molar cyanogen bromide indichloromethane was combined with 19.0 g (100 mmol) of5-chloro-4-hydrazino-2-methylthiopyrimidine and 200 mL of dry isopropylalcohol at ambient temperature with stirring. The resulting mixture wasstirred for 18 hours and then diluted with 500 mL of diethyl ether. Thesolids that formed were recovered by filtration and dried to obtain thetheoretical amount of the title compound as a yellow solid melting above250° C. ¹H NMR (DMSO-d₆): δ 7.80 (s, 1H); 2.67(s, 3H); ¹³C: δ 150.96,147.90, 143.10, 138.38, 113.16, 14.22. Anal. Calc'd for C₆H₇N₅BrClS: C,24.3; H, 2.38; N, 23.6; S, 10.8. Found: C, 26.1; H, 2.69; N, 24.0; S,12.2.

The following 3-amino[1,2,4]triazolo-[4,3-c]pyrimidine compounds wereprepared similarly:

3-Amino-8-methoxy-5-methylthio[1,2,4]triazolo[4,3-c]pyrimidinehydrobromide—a tan solid melting at 180-182° C.; Anal. Calc'd forC₇H₁₀N₅BrOS: C, 28.8; H, 3.45; N, 24.0; S, 11.0. Found: C, 29.0; H,3.44; N, 23.9; S, 11.1.

3-Amino-8-methyl-5-methylthio[1,2,4]triazolo[4,3-c]pyrimidineHydrobromide—a yellow solid melting at 234-236° C.; Anal. Calc'd forC₇H₁₀N₅BrS: C, 30.6; H, 3.30; N, 25.5; S, 11.7. Found: C, 30.7; H, 3.52;N, 25.3; S, 11.5.

15. Preparation of2-Amino-8-chloro-5-methoxy[1,2,4]triazolo[1,5-c]pyrimidine

A mixture of 15.0 g (51 mmol) of3-amino-8-chloro-5-methylthio[1,2,4]triazolo[4,3-c]pyrimidinehydrobromide, 8.2 mL (76 mmol) of ethyl acrylate, and 150 mL of methanolwas prepared and cooled in an ice bath. A solution of 17 mL (76 mmol) of4.5 molar sodium methoxide in methanol was added to this slowly withcooling and stirring. When the addition was complete, the mixture wasallowed to warm to ambient temperature and was stirred for 18 hours. Itwas then neutralized with 2.0 mL of acetic acid. The solids that formedwere recovered by filtration, washed with diethyl ether, and dried toobtain 7.7 g (75 percent of theory) of the title compound as a tanpowder melting above 250° C. ¹H NMR (DMSO-d₆): δ 8.0(s, 1H); 6.6 (brs,2H); 4.1 (s, 3H); ¹³C: δ 166.40, 151.65, 147.73, 140.95, 108.57, 56.12.Anal. Calc'd for C₆H₆N₅ClO: C, 36.1; H, 3.03; N, 35.1. Found: C, 36.1;H, 3.19; N, 34.8.

The following 2-amino[1,2,4]triazolo[1,5-c]pyrimidine compounds wereprepared similarly:

2-Amino-5,8-dimethoxy[1,2,4]triazolo[1,5-c]pyrimidine—a tan powdermelting at 201-203° C.; Anal. Calc'd for C₇H₉N₅O₂: C, 43.1; H, 4.65; N,35.9. Found: C, 43.2; H, 4.67; N, 35.6.

2-Amino-8-methyl-5-methoxy[1,2,4]triazolo[1,5-c]pyrimidine—a tan solidmelting above 250° C.; Anal. Calc'd for C₇H₉N₅O: C, 46.9; H, 5.06; N,39.1. Found: C, 46.7; H, 4.84; N, 39.1.

16. Preparation of 2-Amino-5,8-dimethoxy[1,2,4]triazolo[1,5-a]pyridine

A mixture of 58.4 g (0.21 mole) of ethyl[(3,6-dimethoxypyridin-2-yl)amino]carbonothioylcarbamate, 70 g (1 mole)of hydroxylamine hydrochloride and 105 mL (0.6 mole) ofdiisopropylethylamine in 1 liter of ethanol was heated to reflux for 12hr. After cooling, the resulting solution was evaporated to drynessunder vacuum. Water (250 ml) and diethyl ether (100 ml) were added tothe residue and the mixture was stirred for 15 min. The product wascollected by filtration and dried under a vacuum at room temperature togive 25.2 g of 2-amino-5,8-dimethoxy[1,2,4]triazolo[1,5-a]pyridine.

mp 223-234° C. ¹H NMR (DMSO-d₆): δ 6.9 (d, 1H, j=8.7); 6.2 (d, 1H,j=8.4); 5.9 (s, 2H); 4.0 (s, 3H); 3.8 (s, 3H).

17. Preparation of 2-Amino-5,7-dimethoxy[1,2,4]triazolo[1,5-a]pyrimidine

2-Amino-4,6-dimethoxypyrimidine (5.0 g, 36 mmol) was dissolved in drytetrahydrofuran (THF, 35 mL), ethoxycarbonylisothiocyanate (6.4 mL, 54mmol) was added and the solution was allowed to stir at roomtemperature. After 24 hours, the solvent is removed in vacuo and theresidue was mixed with ether to form a crystalline solid. The solidswere removed by vacuum filtration and dried to afford ethyl[(4,6-dimethoxypyrimidin-2-yl)amino]carbono thioylcarbamate as a tansolid (8.9 g, 87%). mp 196-197° C. ¹H NMR (CDCl₃): δ 13.2 (bs, 1H); 8.8(bs, 1H); 5.80 (s, 1H); 4.32-4.25 (q, 2H, J=7.2); 3.93 (s, 3H); 1.30 (t,3H, J=7.2).

Ethyl [(4,6-dimethoxypyrimidin-2-yl)amino carbonothioylcarbamate (0.50g, 1.7 mmol) was mixed with ethanol (5 mL). To this mixture was addedhydroxylamine hydrochloride (0.12 g, 1.7 mmol) anddiisopropylethyl-amine (0.30 mL, 1.7 mmol). The resulting mixture wasallowed to stir at room temperature. After 2.5 hours, additionaldiisopropylethylamine (0.30 mL, 1.7 mmol) was added to the mixture.After 48 hours the ethanol was removed in vacuo and the residue waspartitioned between H₂O and Et₂O to give a powder. The powder wasfiltered and dried to afford the product as a tan powder (0.27 g, 82%).mp 215-220° C. Anal: Cacld for C₇H₉N₅O₂: C, 43.08; H, 4.65; N, 35.88; O,16.39; found: C, 39.88; H, 4.22; N, 32.00; O, 16.35. ¹H NMR (DMSO-d₆): δ6.04 (s, 1H); 5.97 (br, 2H); 4.04 (s, 3H).

18. Preparation of3-Methoxy-N-(5,8-dimethoxy[1,2,4]triazolo[1,5-c]pyrimidin-2-yl)thiophene-2-sulfonamide(Compound 1)

To a slurry of 0.8 g (4.5 mmol) of2-amino-5,8-dimethoxy[1,2,4]triazolo[1,5-c]pyrimidine in 7 mL ofacetonitrile was added 1.3 g (6.1 mmol) of3-methoxythiophene-2-sulfonylchloride, 0.6 mL of dry pyridine and 0.003mL of dry DMSO. After 96 hr, the reaction mixture was partitioned withCH₂Cl₂ and water. The organic phase was separated, washed with diluteaqueous HCl, dried over MgSO₄, filtered and concentrated. The residuewas taken into a small amount of CH₂Cl₂ before ether was added slowlywith stirring to precipitate a fine tan solid. The solid was collectedby filtration and dried under vacuum to give 0.85 g (50%) of the desiredproduct. mp 227-228° C. ¹H NMR (300 MHz, DMSO-d₆): δ 12.1 (s, 1H); 7.8(d, 1H, J=5.6); 7.6 (s, 1H); 7.0 (d, 1H, J=5.6); 4.1 (s, 3H); 3.9 (s,3H); 3.8 (s, 3H). Calc'd for C₁₂H₁₃N₅O₅S₂: C, 38.81; H, 3.53; N, 18.86;S, 17.27. Found: C, 38.32; H, 3.49; N, 18.91; S, 17.34.

The N-([1,2,4]triazolo[1,5-c]pyrimidin-2-yl)thiophenesulfonamide,N-([1,2,4]triazolo[1,5-a]pyrimidin-2-yl)thiophenesulfonamide, andN-([1,2,4]triazolo[1,5-a]pyridin-2-yl)thiophenesulfonamide compounds ofTables 1 and 2 were prepared similarly.

19. Preparation of Herbicidal Compositions

Wettable Powder

Barden clay (55.5 g), HiSil 233 silica (5.0 g), Polyfon H (sodiumlignosulfonate; 7.0 g), Stepanol ME-Dry (sodium lauryl sulfate; 7.9 g),and Compound 1 (20.4 g) were added to a 1 quart glass Waring blender cupand thoroughly mixed at high speed. The blended mixture was passed (onetime) thru a laboratory Trost mill with the opposing jets set between 75and 80 psi (517-551 kPa). This produced a wettable powder of excellentwettability and suspension power. By diluting this wettable powder withwater it is possible to obtain suspensions of suitable concentrationsfor controlling weeds.

Aqueous Suspension Concentrate

To prepare an aqueous suspension concentrate, deionized water (106 g),Kelzan S (xanthan gum; 0.3 g), Avicel CL-611 (carboxylmethyl cellulose;0.4 g), and Proxel GXL (1,2-benzisothiazolin-3-one; 0.2 g) were added toa blender and mixed for 30 min. Then Compound 6 (44 g), Darvan #1(naphthalene sulfonate; 2 g), Foamaster UDB (silicone fluid; 0.2 g),Pluronic P-105 (ethylene oxide/propylene oxide block copolymer; 20 g),phosphoric acid (0.02 g), and propylene glycol (16 g) were added to thesame blender and mixed for 5 min. Once blended the contents were milledin an Eiger mill filled with 1-1.25 mm lead free glass beads (40 mL) at5000 rpm for 30 min. External cooling on the Eiger mill grinding chamberwas maintained at 15° C.

Oil-based Suspension Concentrate

To a 1 quart glass Waring blender cup was added Exxon's crop oil (145.4g), Amsul DMAP 60 (dimethylaminopropane salt of dodecybenzene sulfonicacid; 4.0 g) and Attagel 50 (attapulsite clay; 4.0 g). The mixture wasthoroughly blended at high speed to insure homogeneity. The Amsul DMAPwas difficult to disperse, but eventually formed small homogeneousglobules. Agrimul 70-A (ethoxylated bismethylene octylphenol; 4.0 g) andEmulsogen M (oleyl alcohol-ethylene oxide; 16.0 g) were added andthoroughly blended until the mixture was uniform in texture.Cloquintocet mexyl (5.4 g) was then blended into the mixture followed byCompound 7 (21.3 g). The final grinding stock dispersion milled in theEiger mill using the conditions described above for the aqueoussuspension concentrate.

20. Evaluation of Postemergence Herbicidal Activity

Seeds of the desired test plant species were planted in Grace-SierraMetroMix® 306 planting mixture, which typically has a pH of 6.0 to 6.8and an organic matter content of about 30 percent, in plastic pots witha surface area of 64 square centimeters. When required to ensure goodgermination and healthy plants, a fungicide treatment and/or otherchemical or physical treatment was applied. The plants were grown for7-21 days in a greenhouse with an approximately 15 hr photoperiod whichwas maintained at about 23-29° C. during the day and 22-28° C. duringthe night. Nutrients and water were added on a regular basis andsupplemental lighting was provided with overhead metal halide 1000 Wattlamps as necessary. The plants were employed for testing when theyreached the first or second true leaf stage.

A weighed amount of each test compound, determined by the highest rateto be tested, was placed in a 20 mL glass vial and was dissolved in 4 mLof a 97:3 v/v (volume/volume) mixture of acetone and dimethyl sulfoxideto obtain concentrated stock solutions. If the test compound did notdissolve readily, the mixture was warmed and/or sonicated. Theconcentrated stock solutions obtained were diluted with an aqueousmixture containing acetone, water, iso-propyl alcohol, dimethylsulfoxide, Atplus 411F crop oil concentrate, and Triton X-155 surfactant(methylenebisdiamyl phenoxy polyethoxy ethanol) in a48.5:39:10:1.5:1.0:0.02 v/v ratio to obtain spray solutions of knownconcentration. The solutions containing the highest concentration to betested were prepared by diluting 2 mL aliquots of the stock solutionwith 13 mL of the mixture and lower concentrations were prepared bydilution of appropriate smaller portions of the stock solution.Approximately 1.5 mL aliquots of each solution of known concentrationwere sprayed evenly onto each of the test plant pots using a DeVilbissatomizer driven by compressed air pressure of 2 to 4 psi (140 to 280kilopascals) to obtain thorough coverage of each plant. Control plantswere sprayed in the same manner with the aqueous mixture. In this testan application rate of 1 ppm results in the application of approximately1 g/ha.

The treated plants and control plants were placed in a greenhouse asdescribed above and watered by sub-irrigation to prevent wash-off of thetest compounds. After 2 weeks the condition of the test plants ascompared with that of the untreated plants was determined visually andscored on a scale of 0 to 100 percent where 0 corresponds to no injuryand 100 corresponds to complete kill. Some of the compounds tested,application rates employed, plant species tested, and results are givenin Table 3.

TABLE 3 POSTMERGENCE HERBICIDAL ACTIVITY Cpd. Rate, No. ppm STEME XANSTCHEAL IPOHE AMARE ABUTH VIOTR POLCO ALOMY SETFA SORBI AVEFA 1 3.9 75 5075 85 95 75 70 98 95 100 98 99 2 7.8 98 60 90 85 98 95 95 90 70 98 98 903 31 70 100 95 70 100 70 80 85 70 85 90 80 4 15.6 60 60 90 60 100 70 6090 70 85 70 60 6 7.8 80 95 80 85 100 90 85 85 80 98 80 70 7 1.9 98 80 6080 — 80 80 — 98 100 98 98 8 7.8 95 60 70 60 — 75 75 — 50 60 95 85 9 6295 60 40 70 — 70 60 — 60 20 70 10 10 15.6 98 100 70 80 95 90 90 70 50 9080 80 11 15.6 80 90 95 70 100 85 75 80 75 100 90 85 12 15.6 95 90 90 9595 95 80 85 60 95 95 85 13 7.8 95 95 90 75 100 95 75 990 80 95 95 85 1431.3 100 95 100 80 95 90 75 95 80 95 95 80 15 15.6 90 90 90 70 90 70 7080 80 100 100 95 16 15.6 90 95 95 60 95 80 70 90 85 90 90 80 17 31.3 9095 100 70 95 85 70 60 70 90 90 85 18 15.6 90 100 90 75 100 85 100 95 7090 100 95 19 15.6 95 95 100 80 100 80 100 95 70 100 100 100 20 31.3 85100 75 75 95 85 90 90 30 50 85 70 21 62.5 100 90 100 80 100 100 90 10030 50 100 75 22 31.3 80 90 90 90 100 70 80 90 60 80 95 50 23 15.6 80 9080 40 90 90 70 75 70 90 90 70 24 7.8 80 90 85 80 100 70 70 70 80 90 10070 25 31 60 90 90 70 90 70 70 70 80 80 95 80 STEME = chickweed(Stellaria media) XANST = cocklebur (Xanthium strumarium) CHEAL =lambsquarters (Chenopodium album) IPOHE = morningglory (Ipomoeahederacea) AMARE = pigweed (Amaranthus retroflexus) ABUTH = velvetleaf(Abutilion theophrasti) VIOTR = viola (Viola tricolor) POLCO = wildbuckwheat (Polygonum convolvulus) ALOMY = blackgrass (Alopecurusmyosuroides) SETFA = giant foxtail (Setaria faberi) SORBI = Rox orangesorghum (Sorghum bicolor) AVEFA = wild oats (Avena fatua)

21. Evaluation of Preemergence Herbicidal Activity

Seeds of the desired test plant species were planted in a soil matrixprepared by mixing a loam soil which was composed of about 43 percentsilt, 19 percent clay, and 38 percent sand and had a pH of about 8.1 andan organic matter content of about 1.5 percent and sand in a 70 to 30ratio. The soil matrix was contained in plastic pots with a surface areaof 161 square centimeters. When required to ensure good germination andhealthy plants, a fungicide treatment and/or other chemical or physicaltreatment was applied.

A weighed amount, determined by the highest rate to be tested, of eachtest compound was placed in a 20 mL glass vial and was dissolved in 8 mLof a 97:3 v/v (volume/volume) mixture of acetone and dimethyl sulfoxideto obtain concentrated stock solutions. If the test compound did notdissolve readily, the mixture was warmed and/or sonicated. The stocksolutions obtained were diluted with a 99.9:0.1 mixture of water andTween® 155 surfactant (ethoxylated sorbitan fatty acid ester) to obtainapplication solutions of known concentration. The solutions containingthe highest concentration to be tested were prepared by diluting 4 mLaliquots of the stock solution with 8.5 mL of the mixture and lowerconcentrations were prepared by dilution of appropriate smaller portionsof the stock solution. A 2.5 mL aliquot of each solution of knownconcentration was sprayed evenly onto the soil of each seeded pot usinga Cornwall 5.0 mL glass syringe fitted with a TeeJet TN-3 hollow conenozzle to obtain thorough coverage of the soil in each pot. Control potswere sprayed in the same manner with the aqueous mixture. A highestapplication rate of 4.48 kg/ha is achieved when 50 mg of test compoundis employed.

The treated pots and control pots were placed in a greenhouse with anapproximately 15 hr photoperiod which was maintained at about 23-29° C.during the day and 22-28° C. during the night. Nutrients and water wereadded on a regular basis and supplemental lighting was provided withoverhead metal halide 1000 Watt lamps as necessary. The water was addedby top-irrigation. After 3 weeks the condition of the test plants thatgerminated and grew as compared with that of the untreated plants thatgerminated and grew was determined visually and scored on a scale of 0to 100 percent where 0 corresponds to no injury and 100 corresponds tocomplete kill or no germination. Some of the compounds tested,application rates employed, plant species tested, and results are givenin Table 4.

TABLE 4 PREEMERGENCE HERBICIDAL ACTIVITY Cpd. Rate, No. g/Ha XANST CHEALIPOHE AMARE ABUTH EPHHL ALOMY ECHCG DIGSA SETFA SORBI AVEFA 1 17.5 70 9885 100 98 100 100 100 100 100 100 100 2 8.8 — 98 80 95 75 90 95 75 100100 100 100 3 35 70 95 60 95 50 70 80 70 95 90 90 70 4 35 0 80 50 100 7040 95 0 90 90 80 60 6 35 70 99 80 100 80 70 75 80 100 100 100 80 7 4.480 — 85 95 95 85 100 99 100 100 100 100 8 8.8 80 70 75 80 70 85 85 25 5060 70 80 9 70 25 — 10 40 30 10 100 0 10 15 50 30 10 8.8 — 95 80 100 7075 90 90 70 90 100 90 11 4.4 50 95 30 90 80 50 100 10 40 100 98 70 128.8 90 100 80 100 90 95 100 100 100 100 100 100 13 4.4 80 100 90 90 80100 100 100 100 100 100 100 14 35 60 98 60 80 80 30 100 98 100 100 100100 15 8.8 60 98 70 85 90 90 100 80 100 100 100 100 16 35 40 80 0 60 400 100 0 30 0 0 0 17 35 70 100 0 70 30 60 100 30 30 60 60 30 18 4.4 90100 80 95 90 90 100 100 98 100 100 80 19 8.8 50 90 90 75 95 90 95 95 100100 95 100 20 17.5 60 70 70 80 80 50 90 95 85 50 90 90 21 8.8 50 70 4060 80 60 70 30 40 70 70 70 22 35 80 98 98 100 100 80 70 100 98 100 10070 23 4.4 70 90 80 100 90 90 98 80 100 98 100 90 24 8.8 70 100 98 90 9880 90 40 98 100 100 70 25 17.5 50 90 60 95 80 80 95 85 85 85 90 80 XANST= cocklebur (Xanthium strumarium) CHEAL = lambsquarters (Chenopodiumalbum) IPOHE = morningglory (Ipomoea hederacea) AMARE = pigweed(Amaranthus retroflexus) ABUTH = velvetleaf (Abutilion theophrasti)EPHHL = wild poinsettia (Euphorbia heterophylla) ALOMY = blackgrass(Alopecurus myosuroides) ECHCG = barnyardgrass (Echinochloa crus-galli)DIGSA = crabgrass (Digitaria sanguinalis) SETFA = giant foxtail (Setariafaberi) SORBI = Rox orange sorghum (Sorghum bicolor) AVEFA = wild oats(Avena fatua)

What is claimed is:
 1. An N-(triazoloazinyl)thiophenesulfonamidecompound of the formula (I):

wherein D and E represent S or CB with the proviso that one of D or E isS; A and B independently represent H, halo, CF₃, R, OR′ or CO₂R″; Trepresents H, SO₂R″, C(O)R″, C(O)OR″, C(O)NR″₂, or CH₂CH₂C(O)OR″; Rrepresents CH₃ or CH₂CH₃; R′ represents C₁-C₄ alkyl, C₃-C₄ alkenyl, orC₃-C₄ alkynyl each optionally possessing up to two chloro, bromo orO(C₁-C₄)alkyl substituents or up to the maximum possible number offluoro substituents; R″ represents H or C₁-C₄ alkyl; and, when Trepresents H, the agriculturally acceptable salts thereof.
 2. A compoundof claim 1 in which T represents H or an agriculturally acceptable saltthereof.
 3. A compound of claim 1 in which D represents S and Erepresents CB.
 4. A compound of claim 3 in which B represents CO₂R″. 5.A compound of claim 1 in which A represents OR′ or CO₂R″.
 6. Acomposition comprising an herbicidal amount of anN-(triazoloazinyl)thiophenesulfonamide compound of the formula (I):

wherein D and E represent S or CB with the proviso that one of D or E isS; A and B independently represent H, halo, CF₃, R, OR′ or CO₂R″; Trepresents H, SO₂R″, C(O)R″, C(O)OR″, C(O)NR″₂, or CH₂CH₂C(O)OR″; Rrepresents CH₃ or CH₂CH₃; R′ represents C₁-C₄ alkyl, C₃-C₄ alkenyl, orC₃-C₄ alkynyl each optionally possessing up to two chloro, bromo orO(C₁-C₄)alkyl substituents or up to the maximum possible number offluoro substituents; R″ represents H or C₁-C₄ alkyl; and, when Trepresents H, the agriculturally acceptable salts thereof, in admixturewith an agriculturally acceptable adjuvant or carrier.
 7. A compositionof claim 6 in which T represents H or an agriculturally acceptable saltthereof.
 8. A composition of claim 6 in which D represents S and Erepresents CB.
 9. A composition of claim 8 in which B represents CO₂R″.10. A composition of claim 6 in which A represents OR′ or CO₂R″.
 11. Amethod of controlling undesirable vegetation which comprises applying tothe vegetation or to the locus thereof an herbicidally effective amountof an N-(triazoloazinyl)thiophenesulfonamide compound of the formula(I):

wherein D and E represent S or CB with the proviso that one of D or E isS; A and B independently represent H, halo, CF₃, R, OR′ or CO₂R″; Trepresents H, SO₂R″, C(O)R″, C(O)OR″, C(O)NR″₂, or CH₂CH₂C(O)OR″; Rrepresents CH₃ or CH₂CH₃; R′ represents C₁-C₄ alkyl, C₃-C₄ alkenyl, orC₃-C₄ alkynyl each optionally possessing up to two chloro, bromo orO(C₁-C₄)alkyl substituents or up to the maximum possible number offluoro substituents; R″ represents H or C₁-C₄ alkyl; and, when Trepresents H, the agriculturally acceptable salts thereof.
 12. A methodof claim 11 in which T represents H or an agriculturally acceptable saltthereof.
 13. A method of claim 11 in which D represents S and Erepresents CB.
 14. A method of claim 13 in which B represents CO₂R″. 15.A method of claim 11 in which A represents OR′ or CO₂R″.